Well screen structure



June 29, 1954 w. J. BANcHBAcK WELL SCREEN STRUCTURE Filed July 14, 1952a 3 3 u R 2 z 0, R f f f 9 9 9 l N V EN TOR. I/z'lliam J azzaaatPatented June 29, 1954 UNITED STATES PATENT OFFICE 6 Claims.

The present invention relates to well screens and comparable devicessuch as drive well points and has for an object the provision of devicesof this kind that are exceptionally strong and eiTcient, and of a methodwhereby they can be made at a reasonable cost.

Another object oi the invention is to provide a structure of this kindincluding longitudinal bars and a helical winding of keystone wiresecured thereto in a manner which provides for mutual mechanicalinterlock and mutual reinforcement of the parts so that accuracy of flowslot size may be maintained under adverse handling conditions.

A further object of the invention is to provide a method of formingdevices of this kind wherein the base of the keystone wire is bentlaterally in slots in the bars thereby strengthening the winding andsimultaneously effecting the interlocking thereof with the bars.

A still further object of the invention is to provide a device of thiskind with a maximum length of accurate and continuous flow slot toafford eiciency in operation.

These and other objects are provided by the means and method describedherein and exemplified in the accompanying drawings in which:

Fig. 1 is a side elevational view of a Well screen embodying theinvention, part being broken away.

Fig. 2 is a cross sectional view taken on line 2-2 of Fig. 1.

Fig. 3 is a cross sectional view taken on line 3-3 of Fig. 1 andillustrating the successive steps in the construction of the device.

In the manufacture of well screens and the like various arrangementshave been used or suggested in attempts to secure, at reasonable cost, astructure that is strong and eicient but all of these have left much tobe desired. The practice of welding the Winding and bars together andthe practice of caulking the metal of the bars and/or winding have bothpresented diiiiculties of one sort of another.

According to the means and method of the present invention I employ akeystone type winding wire 5 of a special shape in which the base or web6 is much higher than the keystone head 'I and secure the turns of suchwire 5 in specially formed angularly turned slots 8 formed in the bars 9of the screen structure as exemplified herein and indicated generally atIII. The bars 9 are wide and may be relatively thin and these areinitially arranged to be held edgewise in radial relation to the centeraxis of the well screen to outline a cylinder about which the keystonehead 'I of the wire is arranged in accurately spaced turns to provide acontinuous and uninterrupted selfcleaning flow slot I I.

The simple, strong and mutually reeniorcing structural connection whicheliminates previous diiliculties in well screen construction consists informing in each bar 9, where the winding intersects it, a slot 8 whichextends perpendicular to the outer edge face I2 of the bar and then hasan angularly turned extension I3. Into each angle slot 8I3 the entirebase or web 6 of the keystone Wire is tted, leaving the head or keystoneportion of the wire to form a helix of spaced turns extending outsidethe outer edge faces I2 of the bars so that the inwardly divergent slotII is continuous and uninterrupted.

As can be best understood from an inspection of Figs. 1 and 3 anydesired number of bars 9, sufcient to support the required Winding toprovide a predetermined flow space II, may be employed. Said bars 9 arearranged edgewise radially of a common center axis and in longitudinalparallelism to form the outline cf a cylinder. Any suitable mandrel (notshown) may be used for holding the bars in position during constructionoi the well screen, and an end coupling member I4 is applied to the bars9 by threaded and/or brazed connection at I5. The bars 9 are bypreference initially unslotted and the bar slots 8--I3 are formedsuccessively in adjacent bars along the path of a helix while the baseof the winding wire is entered and then turned laterally to conform tothe cross section of the slot in the bar.

As will be best understood from an inspection of Fig. 3, if the size ofthe well screen and the size of its flow slot be such that a relativelythicker keystone wire is indicated, then it is desirable that alongitudinal groove I6 be cut along the side face of the wire base 6 toassure bending of the base 6 along the line of said groove as the baseis forced into the angle slot in the bar.

The Wire 5 has its base guidedly fed into the vertical portion 8 of theslot whereupon any suitable pressure means, e. g. a roller indicated indashed lines at I'I forces the leading edge of the base 6 into theangularly related portion I3 of the slot until the slot 8-I3 iscompletely iilled with the base` Ii and the keystone head 'I of the wireextends from the outer edge of the bar. The act of laterally bending thewire to conformity with the cross section of the slot 8-I3 eiects a workhardening of the wire which cooperates to further strengthen the helicalwinding while the laterally turned longitudinal bend is progressivelyformed in the wire.

A strong positive interlocking binding of the wire at each slot in eachof the bars is thus effected. The overall structure of a well screen (ora drive well point) thus formed is strong and rigid and it resistsdistortion under any and all kinds of strains and stresses that may beimposed on it. The metal of the bars is not weakened by caulking of itsmetal as in some known forms of `well screens. Instead the winding andthe bars mutually reenforce each other. The overall weight of materialsmay be appreciably less than in known screens intended and designed foridentical duty.

When the strainer structure is of small diameter and the ow slot ll isvery narrow, a keystone wire therein indicated may have its web thinenough to be bent without the use of a groove such as I6.

The lmethod of speedily making well screens according to the inventionconsists essentially in supporting the bars 9 to outline a cylinder,progressively cutting the angle yslots 8-13 along the path of a helixo'f desired lead, guidedly entering the base of the keystone wire to thefull depth of the vertical slot portion 8 in the bar and finallyexerting force on the top of the keystone head of the wire to cause thebase of the wire to bend laterally into conformity and mutuallyinterlocking relation with the angle slot 8-l 3. The angle slot 8-83 maybe formed in various ways by means forming no part of the presentinvention.

What is claimed is:

1. A well screen device comprising a plurality of thin wide support barsarranged radially edge- Wise about a common center axis, said barshaving angle slots in -spaced relation and disposed along a helical pathabout the plurality of bars, the slots being parallel sided and eachslot entering perpendicularly into the edge of the bar for a distanceand then turning obliquely toward one end of the bar, and a keystoneWire having a parallel sided base entered fully in and laterally bentalong its length into conforming relation to each slot and disposing thekeystone head thereof outwardly of the outer edges of said bars.

2. In a device of the class described the combination of a plurality ofthin wide bars arranged edgewise radially about a common center axis,the bars having slots extending from the outer edges thereofperpendicularly for a distance and then angularly inclined toward acommon end of the bars, and a keystone wire'including a base fittingsnugly into the perpendicular and angularly inclined portions of theslot to form a mechanical interlock of the `wire base in each of saidslots and to provide a longitudinal reenforcing bend in the wire.

3. In well screen the combination of parallel bars arrange-d to outlinea cylinder and successively slotted to define a helical path passingthrough the outer portions of the bars, the slots each extendingradially inwardly from the outermost portions of the bars and thenceinclined toward a common end of said bars to present an angular crosssection shape, and a keystone wire having a keystone shaped head locatedbeyond the open end of the slot and a base having a longitudinalextending reenforcing bend conforming to the cross section of said baseto the cross section of each groove and forming an interlockingpermanent connection of the base of the wire within each Slot in eachbar.

4. The method of making a Well screen which comprises the steps ofdisposing a plurality of bars in parallelism in the outline of acylinder, progressively cutting angle slots in successive bars to dene ahelical path in the plurality of bars, said slots extending from theouter edge of the bar perpendicularly for a `distance and then inclinedangularly toward a common end of the bar, entering the base of akeystone wire into the open top of each slot on completion of thecutting thereof and forthwith subjecting the head of the keystone wireto pressure and causing the base of the wire to bend laterally intocompletely filling and interlocking relation with the sides of the angleslot.

5. The method of making well screens and the like which comprises thesteps of form-ing a shallow longitudinal groove in one side wall of thebase of a keystone wire, arranging a plurality of bars in the outline ofa cylinder, progressively forming angle slots in successive bars along ahelical path, said angle slots being parallel sided and enteringperpendicularly from the outer edge of the bar for a distance and theninclined angularly toward an end of the bar, feeding the base of thewire into the open tops of said slots successively and forthwith forcingthe base of the wire into the successive slots for forming a workhardened reenforcing bend extending longitudinally ci the wire from saidgroove to the vend of the base as said end of the base enters and iillsthe angle slots whereby an interlocking mechaniconnection is completedbetween the wire base and the bars at each slot in-said bars.

6. The method of making well screens .and .the like comprising thesteps-of longitudinally grooving a key-stone wire along one face of .thebase thereof, supporting a plurality -of bars` radially edgewise in theform Aof the -outline of a cylinder, progressively forming parallelsided :angle yslots in successive bars along a helical path about ysaidplurality of bars, the :angle slots each including a top portionextending vfrom the outer Vedge of the bar perpendicular thereto foradistance equal to substantially the distance between the .keystone headof the wire and the groove in the base thereof, said slot extendingang-ularly from Vsaid top portion toward the end of the bar, the tota-lcross sectional area 'of lthe wire base being substantially equal .tothe cross sectional area of the slot, and successively forcing the baseof 4thefkeystone wire into the successive yslots While winding the wireabout the bars for laterally bending the base of the wire to conform theIshape thereof `to the shape of the slot, said bending operation at.least partially closing the groove in the side y0.1i the wire base.

yReferences Cited in the le 'of this patent UNITED STATES PATENTS NumberName Date 691,994 1Webber Jan. 28, 1992 857,313 Stancliff June 18, 1907856,559 Basye Sept. lTI, 19057 1,858,592 Johnson May 17, 1932 2,160,790Swanson May 30, 1939

